Organic polymers have a large number of different chemical structures which cause them to range from solids to high viscosity liquids. These materials resemble each other in their behavior owing to the fact that they are almost always high molecular weight materials which ultimately provide their cured forms the necessary physical properties to allow them to be used in a general category known as plastics which includes almost every known polymer. These polymers are molded, formed, cast, extruded, foamed and otherwise handled in order to obtain millions of products used worldwide.
One category of plastics handling that has rapidly evolved since the 1950's is the foamed product, most notably polystyrene, polyvinylchloride, and polyurethane foams, even though other polymers can also be foamed, such as nylon, polyethylene, polypropylene, polyterephthalates, polyvinyl, alkyl ethers, polyvinylidine chloride, polyvinylidinefluoride and some of the lesser known materials such as polyxylenenes and polysulfones.
Cellular products resulting from the foaming of the above polymers are subject to microbial attack, either because the polymer itself is a food source for such microorganisms or because the reticulated form of the polymer allows the collection of debris which serves as a food source for the microorganisms.
It would be beneficial if the reticulated products themselves could be used in applications wherein preservation of some other medium is desired, for example, pasteurization of milk and milk products. Also, it would be beneficial if the reticulated products could be substituted in other applications where it is desirable to reduce the number of microorganisms in a medium, such as, for example, air or water as disclosed in U.S. Pat. No. 3,730,701, issued May 1, 1973; U.S. Pat. No. 3,817,739, issued June 18, 1974 and U.S. Pat. No. 3,865,728, issued Feb. 11, 1975.
Such similar uses have been anticipated and there are products being sold for domestic use which are foamed products that contain antimicrobial agents. For example, 10,10'-oxybisphenoxarsine (OBPA) has been used in polyurethane foam as an antimicrobially effective carpet underlay. See "Manifestations of Microbiological Growth on Urethane Foam", Proceedings of the Society of Plastics Industries 27th Annual Tech/Mkt. Meeting of the Urethane Division, Oct. 20-22, 1982, Bal Harbour, Florida, page 308, and Modern Floor Coverings, Supplier Slants, "GFC Ranks High In Service, Innovation", page 37, August 1983.
There are certain problems, however, with these types of antimicrobial agents in polyurethane foams. For example, such agents leach from the foams. Further, the leachate-agent, once free from the underlay can move into the carpet itself whereby it can be contacted by humans and pets. Because of the leaching, the antimicrobial effect of the carpet underlay is not durable. Further, it has been demonstrated that such agents, especially OBPA, are adapted-to by the microorganism over a period of time so that the agent is ineffective against future generations of the organisms.
Thus, it is an objective of the instant invention to provide new and improved foamed polymers that will overcome the prior art problems.